The Influence of Throttle Augmented Stability (APCS) and Short Period Control Characteristics on the Landing Approach.

The results of an analysis and flight test research program sponsored by the Naval Air Systems Command are presented. The equivalence between Approach Power Compensator System (APCS) feedbacks and aircraft stability derivatives is shown, and expressions relating these terms to system decoupling are developed in the analysis. Attitude command, washout prefilter, and conventional flight control systems are compared in ground and flight tests. Pseudo-velocity-type APCS configurations were found to provide better flight path control than predominantly angle of attack type APCS configurations for the carrier approach task. For typical levels of aircraft static stability, increasing the short period frequency through a simple pitch attitude command flight control system improved the flight path response. (Author)